What percentage should the relieving capacity of a smaller safety valve not fall below for optimal safety?

In order to ensure the optimal safety of a system, the relieving capacity of a smaller safety valve should be at least 50% of the maximum flow rate that the system can produce. The reason for this is to ensure that the safety valve can adequately relieve pressure in case of an overpressure situation, protecting equipment and personnel from potentially dangerous conditions.

The choice of setting the relieving capacity at 50% strikes a balance between safety and practicality. A valve that has less than 50% capacity may not be able to vent enough pressure quickly enough during an emergency, which could lead to catastrophic failure of the system. Conversely, valves that are set higher than necessary may be unnecessarily expensive and can result in inefficiency or improper sizing.

Thus, maintaining a minimum relieving capacity of 50% is a widely accepted safety standard in piping and pressure systems to ensure that any excess pressure can be managed effectively without compromise.